Optimization of Quantization in Higher Order Modulations for LDPC-Coded Systems
In this paper, we evaluate the choice of suitable
quantization characteristics for both the decoder messages and the
received samples in Low Density Parity Check (LDPC) coded
systems using M-QAM (Quadrature Amplitude Modulation)
schemes. The analysis involves the demapper block that provides
initial likelihood values for the decoder, by relating its quantization
strategy of the decoder. A mapping strategy refers to the grouping of
bits within a codeword, where each m-bit group is used to select a
2m-ary signal in accordance with the signal labels. Further we
evaluate the system with mapping strategies like Consecutive-Bit
(CB) and Bit-Reliability (BR). A new demapper version, based on
approximate expressions, is also presented to yield a low complexity
hardware implementation.
[1] Digital Video Broadcasting (DVB); Second Generation Framing
Structure,Channel Coding and Modulation Systems for roadcasting,
Interactive Services, News Gathering and Other Broadband Satellite
Applications, ETSI EN Std. 302 307 (v1.1.2), Jun. 2006, Rev. 1.1.1.
[2] J. Hagenauer, E. Offer, and L. Papke, "Iterative decoding of binary
block and convolutional codes," IEEE Trans. Inform. Theory, vol. 42,
no. 2, pp. 429-445, Mar. 1996.
[3] R. M. Tanner, A recursive approach to low complexity codes, IEEE
Transactions on Information Theory, vol. 27, IEEE, 1981, pp. 533-547.
[4] John R. Barry, Low-density parity-check codes, Tech. report, Georgia
Institute of Technology, 2001.
[5] R. Pyndiah, A. Picart, and A. Glavieux, "Performance of block turbo
coded 16-QAM and 64-QAM modulations," in Proc. IEEE Global
Telecommunications Conference (GLOBECOM-95), Singapore, Nov.
1995, vol. 2, pp. 1039-1043.
[6] F. Tosato and P. Bisaglia, "Simplified soft-output demapper for binary
interleaved COFDM with application to HIPERLAN/2," in Proc. IEEE
ICC 2002, New York, May 2002, vol. 2, pp. 664-668.
[7] D. Oh and K. K. Parhi, "Performance of quantized min-sum decoding
algorithms for irregular LDPC codes," in Proc. IEEE ISCAS 2007,
New Orleans, LA, May 2007, pp. 2758-2761.
[8] S. Papaharalabos, M. Papaleo, P. T. Mathiopoulos, M. Neri, A.Vanelli-
Coralli, and G. E. Corazza, "DVB-S2 LDPC decoding using robust
check node update approximations," IEEE Trans. Broadcast.,
vol.54,no. 1, pp. 120-126, Mar. 2008.
[1] Digital Video Broadcasting (DVB); Second Generation Framing
Structure,Channel Coding and Modulation Systems for roadcasting,
Interactive Services, News Gathering and Other Broadband Satellite
Applications, ETSI EN Std. 302 307 (v1.1.2), Jun. 2006, Rev. 1.1.1.
[2] J. Hagenauer, E. Offer, and L. Papke, "Iterative decoding of binary
block and convolutional codes," IEEE Trans. Inform. Theory, vol. 42,
no. 2, pp. 429-445, Mar. 1996.
[3] R. M. Tanner, A recursive approach to low complexity codes, IEEE
Transactions on Information Theory, vol. 27, IEEE, 1981, pp. 533-547.
[4] John R. Barry, Low-density parity-check codes, Tech. report, Georgia
Institute of Technology, 2001.
[5] R. Pyndiah, A. Picart, and A. Glavieux, "Performance of block turbo
coded 16-QAM and 64-QAM modulations," in Proc. IEEE Global
Telecommunications Conference (GLOBECOM-95), Singapore, Nov.
1995, vol. 2, pp. 1039-1043.
[6] F. Tosato and P. Bisaglia, "Simplified soft-output demapper for binary
interleaved COFDM with application to HIPERLAN/2," in Proc. IEEE
ICC 2002, New York, May 2002, vol. 2, pp. 664-668.
[7] D. Oh and K. K. Parhi, "Performance of quantized min-sum decoding
algorithms for irregular LDPC codes," in Proc. IEEE ISCAS 2007,
New Orleans, LA, May 2007, pp. 2758-2761.
[8] S. Papaharalabos, M. Papaleo, P. T. Mathiopoulos, M. Neri, A.Vanelli-
Coralli, and G. E. Corazza, "DVB-S2 LDPC decoding using robust
check node update approximations," IEEE Trans. Broadcast.,
vol.54,no. 1, pp. 120-126, Mar. 2008.
@article{"International Journal of Electrical, Electronic and Communication Sciences:59488", author = "M.Sushanth Babu and P.Krishna and U.Venu and M.Ranjith", title = "Optimization of Quantization in Higher Order Modulations for LDPC-Coded Systems", abstract = "In this paper, we evaluate the choice of suitable
quantization characteristics for both the decoder messages and the
received samples in Low Density Parity Check (LDPC) coded
systems using M-QAM (Quadrature Amplitude Modulation)
schemes. The analysis involves the demapper block that provides
initial likelihood values for the decoder, by relating its quantization
strategy of the decoder. A mapping strategy refers to the grouping of
bits within a codeword, where each m-bit group is used to select a
2m-ary signal in accordance with the signal labels. Further we
evaluate the system with mapping strategies like Consecutive-Bit
(CB) and Bit-Reliability (BR). A new demapper version, based on
approximate expressions, is also presented to yield a low complexity
hardware implementation.", keywords = "Low Density parity Check, Mapping, Demapping,
Quantization, Quadrature Amplitude Modulation", volume = "6", number = "1", pages = "102-7", }